Heron and other Preds affecting up to 50% fry returns to ocean

[Bugle M In]

As the title states.
Saw it on the news last night.
Quite something to find out about and shocking to realize many salmon fry never make it out, let alone get back.

I think in a recent study on damage of catch and release salmon ( i will post that one later), that many salmon that return from
the ocean only equates to 1% return. (100,000 @1% = 1000)
And i guess they looked at it as how many salmon were being removed "from the oceans and on their way back up".

So, this changes things a lot potentially and possibly on how we manage in the future i suppose/maybe.
So, cant blame it all on the sportfishing guys and commercial and seals.
But hey, credit at the fellow for looking into it!

[Blacktail1]

Heron are the worst . I attended a seminar put on by pacific salmon foundation last year and I thing they said heron eat salmon 10 to 1 compared to seals. This evidence was collected by finding pit tags from the droppings from heron and also by attaching antennas to seals head that counted pit tags as fish were eaten by seal. I may have details a bit wrong but at any rate herons are not good for salmon .

[adriaticum]

Cormorants are even more deadly. They congregate in estuaries and pick them off when they school.
Especially these hatchery fish that get released in large numbers.

[303savage]

Seals eat a lot of fry too.

[srthomas75]

{ I think in a recent study on damage of catch and release salmon that many salmon that return from
the ocean only equates to 1% return. (100,000 @1% = 1000) }


I think that is a similar percentage rate of return for lots of ocean living creatures. On a trip to Mexico one year we were there for a release of the baby turtles. Out of the hundreds set loose on the beach they expected a few to return at maturity. 2 or 3% if I remember correctly.

[VLD43]

A lot of this is nothing new. Typically there is a 1 to 1.5 % return from a spawning cycle. In some places like Gold River, they were getting 2.5 to 3 % returns. Back then the fishing was amazing up there. It is easy to get focused on natural predation, but it has been going on from time in memorial. To me the biggest concern, is lack of/loss of habitat. It doesn't matter if you get a high percentage return from a spawning cycle if there is no where for the fish to spawn. Some species like chum salmon can spawn in estuaries, but Chinook and especially Coho need clean cool streams to be successful. On the Island, especially the south Island, many of the streams have been devastated by negligent logging practices and lack of Government oversight. There is nothing for the fish to return to. Rivers like the Fraser appear to not have the flows they used to, and the temperature is rising on those waterways. The minute those temperature rise and by how much affects returning fish and the spawn. Fish either die before they get to spawn, or they spawn, and the hatch happens to early because of warm water. When that occurs, the returning fry get back to the Ocean before the plankton blooms happen, and so there is no food to sustain the fry.

[Bugle M In]

Yes, predation has always existed.
And even with that, the salmon still were abundant at one time.
And now, even Heron are in lower #'s these days.
I watched a Patogonia financed film called Artifishal, in a nutshell, that hatcheries were not helping and maybe make things worse (yes, this could be another thread for debate!).
But, behind that, there were 2 points that were apperent and agreed upon by most.
Damming of rivers, thus loss of habitat was issue #1 (whats new!)
The 2nd point, which is also related to Heron #'s, is that most things are in decline.
Its only humans (yes, and seals) that are on the increase.

Those 2 factors pretty much dominate any discussion on any wildlife issues we have.
As humans we think that we are smart enough to solve this with some solutions not yet found/discovered I guess.
But sometimes the hardest things to correct are due to the simplest reasons....too many people, taking up too much space and needing too much of the planet for our own use.

I get the fish farms are bad, and the stupidity of trying to grow a salmon species that doesnt natively reside here is beyond baffling to me.
But one tries to create hatcheries to offset the losses due to habitat destruction, and even that isnt enough or argued by some to be destructive, it sure makes it hard to figure which way to turn.

Good points about the water temps as well.

Just discovering new issues adding to the problem, but really, no viable options on what to do about it.
Definitely discouraging, if not down right depressing when one thinks about the future.
Especially if you like harvesting for yourself off the land.
I already know which group will become "extinct first" (the many of us on here who share in that enjoyment)

[Walking Buffalo]

Bird predation on fry is nothing new to salmon science.
Heck, I learned about this as a pre-teen in the seventies watching cartoons on CBC.


Mortality Stats like these need to be examined much closer than just looking at a single number such as 50%.....

Most importantly how does compensatory mortality quantify with various sources of predation.

[tigrr]

Loons eat a lot of fry as well. During the sockeye fry migration I have seen 15 loons on the river. Them and some mergansers.
Loons are protected!!
Sandhill crane has been opened up for harvest in some areas.

[Bugle M In]

Part of what i felt made this important is that recently there is more and more conversations, mostly coming from the
more Anti side of funding, stating hatcheries are bad.
As i said, last summer i had a long long conversation with a dfo bio for salmon.
And when talking to him, when i mentioned hatcheries, his first words that came from "his mouth" was "we don't like hatcheries".
So, when reading, or in this case, seeing this story of Herons in the news, that many fry don't even get close to hitting the ocean,
it might be a plus for why we need hatcheries, or at least their assistance.
I say assistance because i do feel a river, where the habitat can be properly restored, to allow mostly wild salmon to return, is the
best way, but when so many other things, like the high seal population which looks like that isn't going anywhere soon.
And with the sportfishing industry continuously being reduced or closed, and the save the killer whale etc, whether someone
already knew this info or not, at least many more "not in the know" get to learn about it.

In other words, that clip was a good argument as to "why we need hatcheries" still, when there is a growing push to get rid of
them.

[steel_ram]

I'm pretty sure there is no boom in Heron or any other bird populations so I wouldn't be blaming them on the demise of our fisheries. Harbour seals and Sea Lions may be another matter. I have seen seals 20 miles upstream from tidewater chasing steelhead, but I don't know if this historically normal or an act of desperation.

Hatcheries can't control what happens to the fish once they're at sea. They may very well be overpopulating and overstraining the viable habitat that still exists. I was reading that some of those WA hatchery fish caught by anglers cost over $1000 each to produce.

[Bugle M In]

I'm pretty sure there is no boom in Heron or any other bird populations so I wouldn't be blaming them on the demise of our fisheries. Harbour seals and Sea Lions may be another matter. I have seen seals 20 miles upstream from tidewater chasing steelhead, but I don't know if this historically normal or an act of desperation.

Hatcheries can't control what happens to the fish once they're at sea. They may very well be overpopulating and overstraining the viable habitat that still exists. I was reading that some of those WA hatchery fish caught by anglers cost over $1000 each to produce.
You are correct and that was stated by the study, that Herons are just as much in decline too.
But, if the Herons are in lesser #'s, BUT still having that kind of impact, then do we have too few salmon to begin with!!??
(as far as fry heading down river to ocean)

If Heron with low pops themselves can have that affect, up to 50%, then man, we need more salmon being spawned.
Again, more reason that "hatcheries are still needed"!

[tigrr]

The goal is to not have any salmon and then the natives will be even more dependant on the gov.
Vote liberal so they can give more empty streams and land to the natives.

[Keta1969]

[QUOTE=Bugle M In;2239896]You are correct and that was stated by the study, that Herons are just as much in decline too.
But, if the Herons are in lesser #'s, BUT still having that kind of impact, then do we have too few salmon to begin with!!??
(as far as fry heading down river to ocean)

We have screwed up the ecosystem for both adults and smolts. The Fraser system is a disaster. We have all played a role in it from mining, ranching, logging, in river netting and urban development. The lower Fraser is a cesspool. We catch and release and kill fish for "sport" looking for one the right size all because so we can have an "opportunity". There are discussions under way about fin clipping all hatchery fish and having a catch and release of unclipped wild fish. And this will help how? In the past overfishing played a part, now ocean survival is taking a toll. With a healthy ecosystem fish could bounce back if we took the pressure off. That's no longer the case. By our lifestyles, our jobs and industry and where we live we are asking to much of a few smolts. Yes heron's, loon's, merganzers, seals and sealions take a toll but population and greed will ultimately be responsible. No one wants to be the first to give something up and soon it won't much matter. Sorry for the pessimistic view but I really think that's where we are heading.